The 1851 Census for England was taken on the night of 30 March 1851. The following information was requested:

• Name of street, place, road, etc.
  
• House number or name
  
• Name of each person that had spent the night in that household
  
• Relationship of person enumerated to the head of the family
  
• Person's marital status
  
• Age at last birthday (sex is indicated by which column the age is recorded in)
  
• Person's rank, profession, or occupation
  
• Person's place of birth (if outside of England or Wales, only the country may be given)
  
• Whether blind, deaf, or idiot
  

Enumeration forms were distributed to all households a couple of days before census night and the complete forms were collected the next day. All responses were to reflect the individual's status as of 30 March 1851 for all individuals who had spent the night in the house. People who were traveling or living abroad were enumerated at the location where they spent the night on census night. All of the details from the individual forms were later sorted and copied into enumerators' books, which are the records we can view images of today. The original householders schedules from 1841 to 1901 were destroyed.

The clerks who compiled and reviewed the census data made a variety of marks on the returns. Unfortunately, many of these tally marks were written over personal information and some fields, such as ages, can be difficult to read as a result. More useful marks include a single slash between households within a building and a double slash separating households in separate buildings.

How the census forms are organized:

Census returns were collected according to registration district. These returns were divided into sub-districts and assigned consecutive piece numbers for reference purposes. The piece numbers begin in London with number one and work roughly south to north, followed by the Welsh districts and then the Isle of Man and Channel Islands. You will find the piece number on a paper strip at the bottom of every image, following the PRO class number. There may be hundreds of pieces within a county.

In addition to the piece number, each page of the returns includes a folio number and/or a page number. The folio number was stamped onto every other page before microfilming and is located in the upper right hand corner of the image. Folio numbering usually starts over at the beginning of each piece. The page number is part of the printed form and is found on every page in the upper right hand corner. The page numbers start over at the beginning of every enumeration district. A full reference number for a record in the 1851 census includes the PRO class number (HO 107), the piece number, the folio number, and the page number. Keep in mind that you may have to look at several enumeration districts to find the page you want within a given folio since the page numbers start over with every ED.

Known problems with the 1851 Census:

• The following parishes and hamlets are missing from these piece numbers. Some of these parishes and hamlets represent the entirety of the piece, while others are just portions of a piece.

  Piece	County	Parishes and Hamlets
  1762	Cambridgeshire and Suffolk	Ashley-cum-Silverley Burwell Exning Landwade Newmarket Reach Snailwell St Mary Swaffham Prior
  1763	Cambridgeshire and Suffolk	Dalham Dunstall-Green Gazeley Higham Green Kennett Lidgate Moulton Ousden Southwell Park
  1785	Essex	Aythorp-Roothing Bardfield-Saling Barnston Broxted Chickney Easton Lodge Felstead Great Bardfield Great Canfield Great Dunmow Great Easton Hatfield-Broad-Oak or Hatfield Regis High Easter High Roothing Leaden-Roothing Lindsell Little Bardfield Little Canfield Little Easton Little Dunmow Margaret Roothing Morrell-Roothing Stebbing Takeley Thaxted Tilty White Roothing
  1852	Dorset	Bagbere Bellchalwell Child Okeford Fifehead-Neville Hammoon Haselbury-Bryan Hinton St Mary Ibberton Manston Newton Okeford-Fitzpaine Shillingstone or Shilling-Okeford Stoke-Wake Sturminster-Newton-Castle Woolland

• In addition, the census returns of the following localities have been damaged by water during storage. Most of the damaged pieces are in the area of Manchester. However, through the use of new technology they have now been indexed. The Manchester and Lancashire Family History Society recovered tens of thousands of names working on a small scale to prove the technology. Ancestry.com used forensic and photographic techniques on a large scale to take names from records, which are unreadable by the naked eye because of mold and water damage. The process yielded abt 165,000 names that weren’t previously available.

  Piece	County	Parishes and Hamlets
  2332	Yorkshire	Broadroyd Head Carlton Carr Green Cudworth with High & Low Cudworth Darton Darton Lane Head Darton with Blacker Mapplewell Notton Roystone Staincross & Swallow Hill Woolley
  2219	Lancashire	Manchester Ardwick Birth in Rusholme Burnage Chorlton-dum-Hardy Didsbury Gorton Levenshulme Openshaw Rusholme Withington
  2220	Lancashire	Manchester Ardwick Chorlton-upon-Medlock
  2221	Lancashire	Manchester Moss-side Hulme
  2222/1	Lancashire	Eccles Pendleton
  2222/2	Lancashire	Eccles Pendlebury
  2222/3	Lancashire	Manchester Broughton-with Kersall
  2223	Lancashire	Manchester Salford
  2224	Lancashire	Manchester Salfrod
  2225	Lancashire	Manchester
  2226	Lancashire	Manchester
  2227	Lancashire	Manchester
  2228	Lancashire	Manchester
  2229	Lancashire	Manchester
  2230	Lancashire	Manchester
  2231	Lancashire	Manchester Bradford Beswick Newton with Culcheth & Kirkmanshulme
  2232	Lancashire	Manchester Alt Alt-Edge Alt-Hill Ashton-under-Lyne Blackley Cheetham Crumpsall Failsworth Great Heaton Harpurhey Knott Lanes with Lees Knott Lanes & Wood Park Little Heaton Moston Prestwich Taunton
  2233	Lancashire	Ashton-under-Lyne Ashton Town
  2240	Lancashire	Prestwich Oldham (St Mary's, St Peter's, Wernet, and Westwood Wards)

Connecting piece numbers and localities:

To identify which parishes or townships are included in a piece, please use The National Archives online catalogue. Search the catalogue by entering the series code and the piece number, e.g. HO 107/217, in the box in the upper left that says "Type reference here."

Alternatively, you can search the catalogue vice-versa (identify which piece number a particular parish or township is part of) by putting a place name in the "Word or phrase" field and "HO 107" in the "Department or Series code" field.

Some of the above information was taken from "Chapter 6: Census Returns," Ancestral Trails: The Complete Guide to British Genealogy and Family History by Mark D. Herber (Baltimore, MD: Genealogical Publishing Co., Inc, 1998) and Using Census Returns, Pocket Guides to Family History by David Annal (Richmond, Surrey: Public Record Office, 2002).